#include <stdio.h>
#include <stdlib.h>
#include "string.h"
#include "aes.h"
#include <QDebug>
AES::AES(unsigned char* key)
{
    unsigned char sBox[] =
    { /*  0    1    2    3    4    5    6    7    8    9    a    b    c    d    e    f */
        0x63,0x7c,0x77,0x7b,0xf2,0x6b,0x6f,0xc5,0x30,0x01,0x67,0x2b,0xfe,0xd7,0xab,0x76, /*0*/
        0xca,0x82,0xc9,0x7d,0xfa,0x59,0x47,0xf0,0xad,0xd4,0xa2,0xaf,0x9c,0xa4,0x72,0xc0, /*1*/
        0xb7,0xfd,0x93,0x26,0x36,0x3f,0xf7,0xcc,0x34,0xa5,0xe5,0xf1,0x71,0xd8,0x31,0x15, /*2*/
        0x04,0xc7,0x23,0xc3,0x18,0x96,0x05,0x9a,0x07,0x12,0x80,0xe2,0xeb,0x27,0xb2,0x75, /*3*/
        0x09,0x83,0x2c,0x1a,0x1b,0x6e,0x5a,0xa0,0x52,0x3b,0xd6,0xb3,0x29,0xe3,0x2f,0x84, /*4*/
        0x53,0xd1,0x00,0xed,0x20,0xfc,0xb1,0x5b,0x6a,0xcb,0xbe,0x39,0x4a,0x4c,0x58,0xcf, /*5*/
        0xd0,0xef,0xaa,0xfb,0x43,0x4d,0x33,0x85,0x45,0xf9,0x02,0x7f,0x50,0x3c,0x9f,0xa8, /*6*/
        0x51,0xa3,0x40,0x8f,0x92,0x9d,0x38,0xf5,0xbc,0xb6,0xda,0x21,0x10,0xff,0xf3,0xd2, /*7*/
        0xcd,0x0c,0x13,0xec,0x5f,0x97,0x44,0x17,0xc4,0xa7,0x7e,0x3d,0x64,0x5d,0x19,0x73, /*8*/
        0x60,0x81,0x4f,0xdc,0x22,0x2a,0x90,0x88,0x46,0xee,0xb8,0x14,0xde,0x5e,0x0b,0xdb, /*9*/
        0xe0,0x32,0x3a,0x0a,0x49,0x06,0x24,0x5c,0xc2,0xd3,0xac,0x62,0x91,0x95,0xe4,0x79, /*a*/
        0xe7,0xc8,0x37,0x6d,0x8d,0xd5,0x4e,0xa9,0x6c,0x56,0xf4,0xea,0x65,0x7a,0xae,0x08, /*b*/
        0xba,0x78,0x25,0x2e,0x1c,0xa6,0xb4,0xc6,0xe8,0xdd,0x74,0x1f,0x4b,0xbd,0x8b,0x8a, /*c*/
        0x70,0x3e,0xb5,0x66,0x48,0x03,0xf6,0x0e,0x61,0x35,0x57,0xb9,0x86,0xc1,0x1d,0x9e, /*d*/
        0xe1,0xf8,0x98,0x11,0x69,0xd9,0x8e,0x94,0x9b,0x1e,0x87,0xe9,0xce,0x55,0x28,0xdf, /*e*/
        0x8c,0xa1,0x89,0x0d,0xbf,0xe6,0x42,0x68,0x41,0x99,0x2d,0x0f,0xb0,0x54,0xbb,0x16  /*f*/
    };
    unsigned char invsBox[256] =
    { /*  0    1    2    3    4    5    6    7    8    9    a    b    c    d    e    f  */
        0x52,0x09,0x6a,0xd5,0x30,0x36,0xa5,0x38,0xbf,0x40,0xa3,0x9e,0x81,0xf3,0xd7,0xfb, /*0*/
        0x7c,0xe3,0x39,0x82,0x9b,0x2f,0xff,0x87,0x34,0x8e,0x43,0x44,0xc4,0xde,0xe9,0xcb, /*1*/
        0x54,0x7b,0x94,0x32,0xa6,0xc2,0x23,0x3d,0xee,0x4c,0x95,0x0b,0x42,0xfa,0xc3,0x4e, /*2*/
        0x08,0x2e,0xa1,0x66,0x28,0xd9,0x24,0xb2,0x76,0x5b,0xa2,0x49,0x6d,0x8b,0xd1,0x25, /*3*/
        0x72,0xf8,0xf6,0x64,0x86,0x68,0x98,0x16,0xd4,0xa4,0x5c,0xcc,0x5d,0x65,0xb6,0x92, /*4*/
        0x6c,0x70,0x48,0x50,0xfd,0xed,0xb9,0xda,0x5e,0x15,0x46,0x57,0xa7,0x8d,0x9d,0x84, /*5*/
        0x90,0xd8,0xab,0x00,0x8c,0xbc,0xd3,0x0a,0xf7,0xe4,0x58,0x05,0xb8,0xb3,0x45,0x06, /*6*/
        0xd0,0x2c,0x1e,0x8f,0xca,0x3f,0x0f,0x02,0xc1,0xaf,0xbd,0x03,0x01,0x13,0x8a,0x6b, /*7*/
        0x3a,0x91,0x11,0x41,0x4f,0x67,0xdc,0xea,0x97,0xf2,0xcf,0xce,0xf0,0xb4,0xe6,0x73, /*8*/
        0x96,0xac,0x74,0x22,0xe7,0xad,0x35,0x85,0xe2,0xf9,0x37,0xe8,0x1c,0x75,0xdf,0x6e, /*9*/
        0x47,0xf1,0x1a,0x71,0x1d,0x29,0xc5,0x89,0x6f,0xb7,0x62,0x0e,0xaa,0x18,0xbe,0x1b, /*a*/
        0xfc,0x56,0x3e,0x4b,0xc6,0xd2,0x79,0x20,0x9a,0xdb,0xc0,0xfe,0x78,0xcd,0x5a,0xf4, /*b*/
        0x1f,0xdd,0xa8,0x33,0x88,0x07,0xc7,0x31,0xb1,0x12,0x10,0x59,0x27,0x80,0xec,0x5f, /*c*/
        0x60,0x51,0x7f,0xa9,0x19,0xb5,0x4a,0x0d,0x2d,0xe5,0x7a,0x9f,0x93,0xc9,0x9c,0xef, /*d*/
        0xa0,0xe0,0x3b,0x4d,0xae,0x2a,0xf5,0xb0,0xc8,0xeb,0xbb,0x3c,0x83,0x53,0x99,0x61, /*e*/
        0x17,0x2b,0x04,0x7e,0xba,0x77,0xd6,0x26,0xe1,0x69,0x14,0x63,0x55,0x21,0x0c,0x7d  /*f*/
    };
    memcpy(Sbox, sBox, 256);
    memcpy(InvSbox, invsBox, 256);
    KeyExpansion(key, w);
}

AES::~AES()
{

}

unsigned char* AES::Cipher(unsigned char* input)//加密
{
    unsigned char state[4][4];
    int i,r,c;
    for(r=0; r<4; r++)
    {
        for(c=0; c<4 ;c++)
        {
            state[r][c] = input[c*4+r];//数组初始化
        }
    }
    AddRoundKey(state,w[0]);//先异或轮密钥
    for(i=1; i<=10; i++)//10轮
    {
        SubBytes(state);//字节代替
        ShiftRows(state);//行移位
        if(i!=10)MixColumns(state);//列混合，最后一轮不进行列混合
        AddRoundKey(state,w[i]);//异或轮密钥
    }
    for(r=0; r<4; r++)//输出结果
    {
        for(c=0; c<4 ;c++)
        {
            input[c*4+r] = state[r][c];
        }
    }
    return input;
}
unsigned char* AES::InvCipher(unsigned char* input)//解密
{
    unsigned char state[4][4];
    int i,r,c;
    for(r=0; r<4; r++)//state中存入密文
    {
        for(c=0; c<4 ;c++)
        {
            state[r][c] = input[c*4+r];
        }
    }
    AddRoundKey(state, w[10]);//异或轮密钥
    for(i=9; i>=0; i--)//10轮
    {
        InvShiftRows(state);//行移位
        InvSubBytes(state);//字节代替
        AddRoundKey(state, w[i]);//异或轮密钥
        if(i){
            InvMixColumns(state);}//列混淆
    }
    for(r=0; r<4; r++)
    {
        for(c=0; c<4 ;c++)
        {
            input[c*4+r] = state[r][c];
        }
    }
    return input;
}
void* AES::Cipher(void* input, int length)
{
    unsigned char* in = (unsigned char*) input;
    int i;
    if(!length)
    {
        while(*(in+length++));
        in = (unsigned char*) input;
    }
    for(i=0; i<length; i+=16)
    {
        Cipher(in+i);
    }
    return input;
}

void* AES::InvCipher(void* input, int length)
{
    unsigned char* in = (unsigned char*) input;
    int i;
    for(i=0; i<length; i+=16)
    {
        InvCipher(in+i);
    }
    return input;
}

void AES::KeyExpansion(unsigned char* key, unsigned char w[][4][4])//密钥扩展
{
    int i,j,r,c;
    unsigned char rc[] = {0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36};
    for(r=0; r<4; r++)
    {
        for(c=0; c<4; c++)
        {
            w[0][r][c] = key[r+c*4];
        }
    }
    for(i=1; i<=10; i++)
    {
        for(j=0; j<4; j++)
        {
            unsigned char t[4];
            for(r=0; r<4; r++)
            {
                t[r] = j ? w[i][r][j-1] : w[i-1][r][3];
            }
            if(j == 0)
            {
                unsigned char temp = t[0];
                for(r=0; r<3; r++)
                {
                    t[r] = Sbox[t[(r+1)%4]];
                }
                t[3] = Sbox[temp];
                t[0] ^= rc[i-1];
            }
            for(r=0; r<4; r++)
            {
                w[i][r][j] = w[i-1][r][j] ^ t[r];
            }
        }
    }
}

unsigned char AES::FFmul(unsigned char a, unsigned char b)
{
    unsigned char bw[4];
    unsigned char res=0;
    int i;
    bw[0] = b;
    for(i=1; i<4; i++)
    {
        bw[i] = bw[i-1]<<1;
        if(bw[i-1]&0x80)
        {
            bw[i]^=0x1b;
        }
    }
    for(i=0; i<4; i++)
    {
        if((a>>i)&0x01)
        {
            res ^= bw[i];
        }
    }
    return res;
}

void AES::SubBytes(unsigned char state[][4])//字节代替
{
    int r,c;
    for(r=0; r<4; r++)
    {
        for(c=0; c<4; c++)
        {
            state[r][c] = Sbox[state[r][c]];
        }
    }
}

void AES::ShiftRows(unsigned char state[][4])//行移位
{
    unsigned char t[4];
    int r,c;
    for(r=1; r<4; r++)
    {
        for(c=0; c<4; c++)
        {
            t[c] = state[r][(c+r)%4];
        }
        for(c=0; c<4; c++)
        {
            state[r][c] = t[c];
        }
    }
}

void AES::MixColumns(unsigned char state[][4])//列混合
{
    unsigned char t[4];
    int r,c;
    for(c=0; c< 4; c++)
    {
        for(r=0; r<4; r++)
        {
            t[r] = state[r][c];
        }
        for(r=0; r<4; r++)
        {
            state[r][c] = FFmul(0x02, t[r])
                        ^ FFmul(0x03, t[(r+1)%4])
                        ^ FFmul(0x01, t[(r+2)%4])
                        ^ FFmul(0x01, t[(r+3)%4]);
        }
    }
}

void AES::AddRoundKey(unsigned char state[][4], unsigned char k[][4])
{
    int r,c;
    for(c=0; c<4; c++)
    {
        for(r=0; r<4; r++)
        {
            state[r][c] ^= k[r][c];
        }
    }
}

void AES::InvSubBytes(unsigned char state[][4])
{
    int r,c;
    for(r=0; r<4; r++)
    {
        for(c=0; c<4; c++)
        {
            state[r][c] = InvSbox[state[r][c]];
        }
    }
}

void AES::InvShiftRows(unsigned char state[][4])
{
    unsigned char t[4];
    int r,c;
    for(r=1; r<4; r++)
    {
        for(c=0; c<4; c++)
        {
            t[c] = state[r][(c-r+4)%4];
        }
        for(c=0; c<4; c++)
        {
            state[r][c] = t[c];
        }
    }
}

void AES::InvMixColumns(unsigned char state[][4])
{
    unsigned char t[4];
    int r,c;
    for(c=0; c< 4; c++)
    {
        for(r=0; r<4; r++)
        {
            t[r] = state[r][c];
        }
        for(r=0; r<4; r++)
        {
            state[r][c] = FFmul(0x0e, t[r])
                        ^ FFmul(0x0b, t[(r+1)%4])
                        ^ FFmul(0x0d, t[(r+2)%4])
                        ^ FFmul(0x09, t[(r+3)%4]);
        }
    }
}
void AES::print(unsigned char* state)//输出16个字节的ASCII码
{
    int i;
    for(i=0; i<16; i++)
    {
        printf("%s%X ",state[i]>15 ? "" : "0", state[i]);
    }
    printf("\n");
}
void AES::Initialize()
{
    int l=input.length();//明文长度
    int n;
    int m=l/16+1;//AES轮数
    if(l%16==0)//是128的倍数
    {
        n=16;//要填16个字节的0
    }else{
        n=16-l%16;//应该填充的0的个数
        qDebug()<<"helo in there";
    }
    aes_pading=n;
    aes_rounds=m;
    qDebug()<<"l"<<l;
    qDebug()<<"aes_pading "<<n;
    qDebug()<<"aes_rounds "<<m;
}
void AES::aes_encrypt(){//加密，先例化，再初始化，再加密,输入QString 输出QByteArray
    int l=input.toUtf8().length();//明文长度
    int n;
    int m=l/16+1;//AES轮数
    if(l%16==0)//是128的倍数
    {
        n=16;//要填16个字节的0
    }else{
        n=16-l%16;//应该填充的0的个数
    }
    aes_pading=n;
    aes_rounds=m;
    qDebug()<<"l"<<l;
    qDebug()<<"aes_pading "<<n;
    qDebug()<<"aes_rounds "<<m;
    //填充
    int i;
    int cursur=0;
    QByteArray rslt;
    rslt.append(input);
    QByteArray s;
    s.fill('0',aes_pading);
    rslt.append(s);
    qDebug()<<s;
    rslt.append(s);
    /*for(i=0;i<rslt.size();i++){//输出 rslt数组查看一下
        std::cout<<rslt[i];
        if((i+1)%4==0)
            std::cout<<"\n";
    }*/
    //加密
    output2.clear();
    for(i=0;i<aes_rounds;++i){
        //std::cout<<"\n this is "<<i<<" time aes \n";
        QByteArray tmp((char*)qstrdup(rslt.mid(cursur,16).data()));//tmp保存16个字节
        std::cout<<"the size of tmp: "<<tmp.length()<<"\n";
        Cipher(tmp.data());
        output2.append(tmp);
        qDebug()<<output2;
        qDebug()<<output2.length();
        //std::cout<<tmp.toStdString();
        output=output+QString::fromLocal8Bit(tmp);
        cursur+=16;
    }
}
void AES::aes_decrypt(){//输入QByteArray 输出QString,解密不需要填充
    output.clear();
    int l=input2.length();//明文长度
    int n=0;//n为填充的0的个数
    int m=l/16;//AES轮数
    aes_pading=n;
    aes_rounds=m;
    qDebug()<<"l"<<l;
    qDebug()<<"aes_pading "<<n;
    qDebug()<<"aes_rounds "<<m;
    /*for(i=0;i<rslt.size();i++){//输出 rslt数组查看一下
        std::cout<<rslt[i];
        if((i+1)%4==0)
            std::cout<<"\n";
    }*/
    int cursur=0;
    int i;
    //解密
    for(i=0;i<aes_rounds;++i){
        QByteArray tmp;//tmp保存16个字节，截取input2
        tmp=input2.mid(cursur,16);
        std::cout<<"the size of tmp: "<<tmp.length()<<"\n";
        InvCipher((unsigned char*)tmp.data());
        //std::cout<<tmp.toStdString();
        output=output+QString::fromUtf8(tmp);
        cursur+=16;
    }
}
